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Thread: Deciding if I should SLAM or not

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    Smile Deciding if I should SLAM or not

    My water is crystal clear, but this being my first year on TFP, I am closely monitoring my chlorine levels.
    I have come along way in the past two weeks. I started with an estimated CYA of 120 (half pool water and half tap water to 7ml mark then 7ml of R-0013; water level was at 60 ~ CYA:120) when I started out After getting the CYA under control, I am focusing on Chlorine and making sure all algae and bacteria are killed in the pool.

    All that being said, I'm not sure if I should SLAM or not. Last night around 9:00pm I added bleach to get my FC to 9.5.
    This morning at 4:45am, my FC was 5.5 and the pressure was up on my sand filter ~25%.
    Since then, I have backwashed and added more bleach to bring FC back up to 9.5.

    I am letting my filter run 24/7 and maintaining 9.5 FC levels today (Checking every couple of hours) but not sure if I should go ahead and do the full SLAM or not.

    Reading through other post, I can say the FC consumption are not from hidden algae in steps or lights as there are no lights in the pool, and the ladders and hand rail have not been setup yet.

    I have also read the Chlorine / CYA Chart and for my CYA of 50, my target FC is between 6-8, so I am keeping my chlorine just above that so FC doesn't settle below the minimum.

    FC 9.5
    CC 0 (Why is CC not on the Pool Math App by the way?)
    pH 7.2
    TA 70
    CH 200
    CYA 50

    IMG_2302.jpg
    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Mod Squad Texas Splash's Avatar
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    Re: Deciding if I should SLAM or not

    Last night around 9:00pm I added bleach to get my FC to 9.5. This morning at 4:45am, my FC was 5.5 and the pressure was up on my sand filter ~25%.
    This statement seems to answer the question - SLAM. Loosing 4 ppm overnight is simply too much. Shoot, we don't like to see that much loss over 24 hrs which includes the sun's UV. The pressure increase tells us your filter is working overtime against organics material you simply cannot see. The sooner you start the SLAM the sooner you'll get done. By the looks of things, it shouldn't take incredibly long. You have a very nice looking pool. Good job on the proper test kit, adjusting yoru CYA, and managing things properly. You're doing it the right way.

    PS ~ The reason you don't see CC on the chart is that it's not something we adjust directly. CCs are a by-product of the oxidation process as your free chlorine attacks contaminants in the water. It can fluctuate slightly based on those actions and the available UV light. It's more of an "indicator" or alarm to us rather than a chemical we adjust. Hope that helps.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
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    Re: Deciding if I should SLAM or not

    Reinforcing what Texas Splash, you need to SLAM the pool, no doubt.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
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    Mod Squad woodyp's Avatar
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    Re: Deciding if I should SLAM or not

    This morning at 4:45am, my FC was 5.5 and the pressure was up on my sand filter ~25%.
    MORE than a direct fail of the OCLT.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

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    Re: Deciding if I should SLAM or not

    Newbie here, but I have been lurking in the forum shadows for a few weeks now and I have come to the realization that if you are asking yourself if you need to SLAM bc of the math, then you probably do Your pool looks really nice!
    18x36 vinyl, 26k gallon, liquid chlorine, TF-100 test kit, Doheny Discovery Robot aka Ralphie, Hayward Super Pump VS 230v - SP2603VSP

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    Re: Deciding if I should SLAM or not

    Thanks everyone! I've made a stop to Walmart, and have stocked up on liquid chlorine (10%) and have my pool at FC 20 right now. Let's see how this goes.

    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Re: Deciding if I should SLAM or not

    It's been just over an hour, and the pool is still holding at 20 FC.


    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Re: Deciding if I should SLAM or not

    Is your filter/pump running 24/7? Are you brushing?


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    Re: Deciding if I should SLAM or not

    Quote Originally Posted by domct203 View Post
    Is your filter/pump running 24/7? Are you brushing?


    Sent from my iPhone using Tapatalk
    Yes, the filter is running 24/7, and I'm brushing every hour or so. I am going to give it another hour and check the chlorine again.
    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Re: Deciding if I should SLAM or not

    Last Night (9:30pm) FC - 21.5
    This Morning (5am) FC - 19.5

    So I have lost 2ppm overnight, and according to the OLCT test, I need to keep SLAMing. The pressure on my sand filter over the past 24 hours has only gone up about 2 PSI. Hopefully tonight will be the final night.
    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Mod Squad Texas Splash's Avatar
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    Re: Deciding if I should SLAM or not

    I agree. Maintain the SLAM and hopefully this will be a short-lived process. Also, I couldn't tell from your pic above, but if you have a light, you might consider pulling it out to look behind for algae. Very common hiding place. Have a nice day!
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

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    Re: Deciding if I should SLAM or not

    Quote Originally Posted by Texas Splash View Post
    I agree. Maintain the SLAM and hopefully this will be a short-lived process. Also, I couldn't tell from your pic above, but if you have a light, you might consider pulling it out to look behind for algae. Very common hiding place. Have a nice day!
    Thanks Texas for the support. I vacuumed the pool this morning which had a few leaves, but thats about all. I do not have any lights. Could algae be hiding somewhere else? Is it possible Algae could be inside my return jets?

    IMG_2307.jpg
    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Mod Squad Texas Splash's Avatar
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    Re: Deciding if I should SLAM or not

    Wow, that water sure looks good. We don't see algae in return jets all that often unless the pool sat un-used for a long time. Removing jets sometimes opens-up a new can of problems. :hammer" Since you have nothing else in the water that could hold algae, I'd let the SLAM do its thing today and give the OCLT another shot tonight/tomorrow and see how much you lose. If it fails again, the only thing I can thing of is perhaps a good deep cleaning of the sand. As clear as your water looks now though, I'd leave that as a last option.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

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    Re: Deciding if I should SLAM or not

    Same story, just a different day. Last night 9:45 FC - 18. This morning 4:30 FC - 16. However the pressure gauge hasn't raised in 2 days.
    I am tempted to clean out the sand filter, but am not convinced this is the issue.

    THEORY: If I put the multi-valve on "Recirculate" instead of "Filter" at night, I should be able to test the water overnight and see if it does drop any. Correct?
    If the pool doesn't drop any PPM overnight on recirculate, then the sand filter needs to be cleaned.

    Does this sound right to you guys?
    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Mod Squad Texas Splash's Avatar
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    Re: Deciding if I should SLAM or not

    THEORY: If I put the multi-valve on "Recirculate" instead of "Filter" at night, I should be able to test the water overnight and see if it does drop any. Correct?
    If the pool doesn't drop any PPM overnight on recirculate, then the sand filter needs to be cleaned.
    Hummm. Well, it sounds like a possible way to isolate a problem. But in your pool, with absolutely nothing else in the water, it sounds like that must be the culprit.

    Or, you could simply give this whole process a day or two and monitor so you don't get burnt-out. We start to get obsessed with testing, drips, water levels, and all sorts of stuff. Occasionally, testing variances play a part as well. I would say do what you feel comfortable trying as long as you keep your sanity.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

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    Re: Deciding if I should SLAM or not

    Alright, so last night I ran the filter on recirculate, and the pool didn't drop FC at all! So I suppose the next step is to change out the sand?


    34 X 19 23,000 Gallons; Vinyl Liner; Built 1984
    300lb Howard sandfilter - single speed motor
    1 skimmer, 1 main drain, 2 returns.
    Dolphin S300i Robot Cleaner
    TF-Test Kit

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    Mod Squad woodyp's Avatar
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    Re: Deciding if I should SLAM or not

    If you simply MUST do something, I'd advise just doing a deep clean of that sand filter. You risk damaging those delicate laterals by taking it apart, emptying, and refilling with sand. NOTHING is growing in there. Maybe your SLAM just finally caught up.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

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